Adrenocortical carcinoma (ACC) is a rare but aggressive malignancy of the adrenal cortex. This cancer affects 1 to 2 people per million per year and accounts for 0.02-0.2% of all cancer deaths. Approximately half of all patients have metastatic disease at the time of diagnosis resulting in an average five-year survival of less than 10%. Currently, there is limited knowledge regarding the initiation and pathophysiology of ACC and a lack of effective therapies to treat this disease.
Benign adrenocortical tumors are a much more common occurrence with approximately 5% of people over 50 years old having at least one adrenal mass. These tumors often share many imaging characteristics with their ACC counterparts and therefore determining if a tumor is benign or malignant is not always straightforward. Metastatic disease or local invasion is the only absolute indicator of malignancy. Masses without these features are assessed preoperatively based on size, and imaging characteristics, although the findings of these studies often are unable to definitively categorize the tumor as benign or malignant. After resection, tumor pathology is assessed based on several histologic criteria including cell morphology, cellular proliferation, and tumor invasiveness (Weiss criteria). However for some tumors, with some suspicious features, a definitive diagnosis may not be possible. Accurate diagnosis is critical since the prognosis, follow up, and therapeutic strategy for ACC is much different than that for a benign tumor. Therefore, there is a need for better diagnostic tools for assessing adrenocortical tumors, preoperatively and as an adjunct to routine histopathology.